A configuration for a refrigerating device is known where, in order to prevent breakages and lower performance of a compressor which configures a refrigerant circuit due to overheating, a temperature of a discharge pipe of the compressor is monitored and a protection control is performed on the compressor in a case where this temperature is larger than a determination temperature.
Here, to protect the compressor, it is more desirable to monitor the temperature inside the compressor which has a higher temperature than the temperature of the discharge pipe, in more detail, to monitor the temperature of refrigerant immediately after being discharged from a compression chamber (the temperature of a discharge port) or the temperature of a motor, than to monitor the temperature of the discharge pipe of the compressor. However, since there are difficulties in that arranging a temperature detector inside the compressor because of the hike of the manufacturing cost, a determination temperature is set on the premise that there is a fixed difference in temperatures between the temperature of the inside of the compressor and the temperature of the discharge pipe and the protection control is performed using the temperature of the discharge pipe of the compressor.
Here, in a case where an inverter compressor is used, the difference in temperatures between the temperature of the inside of the compressor and the temperature of the discharge pipe may change since there are changes in the circulating amount of refrigerant. With regard to this, a configuration is disclosed in Japanese Unexamined Patent Application Publication No. 2002-107016 where the determination temperature is modified according to the driving frequency of the inverter compressor (the circulating amount of refrigerant).